Page 120 - Active Science 5 Ebook and Activity

Let’s Recapitulate

Match the following.

A B
1. Taj Mahal a. the sedimentary rock, sandstone

2. Silica b. igneous rock, granite
3. Quartzite is formed from c. sedimentary rock, shale
4. Gneiss is formed from d. white marble

5. Slate is formed from e. contains quartzite

Minerals

The matter of the earth is made up of many elements. Few of these elements are found
in pure form. Most others are found in the form of compounds. Any natural element or
compound in the earth’s crust is called mineral. There are two types of minerals.

1. Metallic Minerals: Rocks contain

several useful minerals. Many minerals
contain metals. These are called
metallic minerals. Rocks containing

minerals that can be extracted
profitably are called ores. Some ores
are bauxite, pyrite, etc. Iron, copper,
gold and aluminium are extracted from Gold Necklace
their respective ores. Some precious Silver Coins

metals are gold, silver, platinum, etc.

2. Non-metallic Minerals: Many minerals
do not have metals in them. These
are called non-metallic minerals.

Diamond is the hardest non-metallic
mineral known. Silica, lime, feldspar,
quartz, graphite, mica are other Diamond Coal
examples of non-metallic minerals.

Some minerals are in the form of crystals. They are hard Do You Know?
and can be polished into gemstones which are usually • Talc is the softest material
used in making jewellery. These are diamond, sapphire, known on earth.
ruby, emerald, etc. These are available in different • The word ‘diamond’ has

beautiful colours like red, green, blue, yellow, etc. They been derived from the Greek
word ‘adamas’ which means
can be called gemstones or precious stones.
‘indestructible’.

120 Active Science-5